In shaving systems of the wet shave type, factors such as the frictional drag of the razor across the skin, the force needed to sever hairs, and irritation of pre-existing skin damage can create a degree of shaving discomfort. Discomfort, and other problems accompanying wet shaving systems, can be alleviated by the application of shaving aids to the skin Shaving aids can be applied prior to, during, or after shaving. A number of problems accompany the use of pre- and post-applied shaving aids. Pre-applied shaving aids can evaporate or can be carried away from the site of application by repeated strokes of the razor. Post-applied shaving aids are not present on the skin during shaving and thus their application can be too late to prevent an unwanted affect. Use of both pre-applied and post-applied shaving aids add additional steps to the shaving process.
Proposals have been made to incorporate a shaving aid e.g., lubricant, whisker softener, razor cleanser, medicinal agent, cosmetic agent or combination thereof, into a razor, e.g., by depositing a shaving aid in a recess on the razor, by incorporating a shaving aid directly into one or more molded polymeric components of the razor, by adhesively securing a shaving aid composite to the razor, and by use of a mechanical connection between a shaving aid composite and the razor. A water soluble shaving aid, e.g., polyethylene oxide, has been dispersed in a matrix of a water insoluble material, e.g., a polystyrene polymer, to form a skin engaging member also known as a shaving aid strip, a shaving aid composite, or a lubricating strip. The skin engaging member has been mounted in or on razor and shaving cartridge structures, adjacent the shaving edge or edges, of single or multiple blade shaving systems as disclosed in U.S. Pat. Nos. 4,170,821 to Booth and 5,113,585 to Rogers. Upon exposure to water, the water-soluble shaving aid leaches from the matrix of the skin engaging member onto the skin.
One problem associated with razor cartridges having a water soluble shaving aid is that a user has no indication when the razor cartridge is nearing the end of its optimal shave performance and should be replaced. One solution to this problem has been to utilize the skin engaging member or lubricating strip to provide an indication or signal to the user that the cartridge has reached the end of its optimal shave performance and should be replaced. Such solutions include the use of a two colored lubrication strip. As the user shaves the lubrication member wears away. Typically, in two color systems one of the layers, e.g., the first layer which can be colored blue, is positioned to wear away first thus exposing the second layer which has a different color than the first layer, e.g., white. This provides an indication to the user that the razor cartridge should be replaced.
One problem associated with the multi-color lube strip indicators is that they are generally ineffective for e.g. a vision-impaired user.